Résumé
Recent evidence suggest that group A beta-hemolytic streptococcal [GABHS] infection may increase the risk of pediatric autoimmune neuropsychiatric disorders [PANDAS] composed of the clinical signs of obsessive-compulsive and attention deficit hyperactivity disorders. The objective of this study was to compare the titer of antibodies against GABHS between children with PANDS and the controls. This cross-sectional, case-control study was done in Hazrat Rasoul Hospital, in Tehran, Iran during 2008-2010. We compared serum antibodies streptolysin O, deoxyribonuclease B, and streptokinase against GABHS quantitatively in 79 cases with PANDAS and 39 age-matched controls. The area under ROC curve, sensitivity, specificity and positive predictive value [PPV] of tests were calculated. Most cases were studied in summer [57%] and spring [23%]. The three aforesaid antibodies were higher in the cases [P=0.001]. Antisterptolysin O [cut-off point 195] had a 90% sensitivity, 82% specificity and a 92% PPV, [CI=95%, 0.99-0.91]. Anti streptokinase [cut-off point 223] had an 82% sensitivity, 82% specificity and a 95% PPV, [CI=95%, 0.934-0.735]. Anti-DNase [cut-off point 140] had an 82% sensitivity, 82% specificity and a 95% PPV, [CI=95%, 0.99-0.91]. The study demonstrated a possible role for streptococcal infection in PANDAS. We found a significantly higher antibody titer against GABHS in OCD and ADHD cases in comparison with healthy children. Treatment of streptococcal infection is achievable by the use of long-acting penicillin. Use of aggressive treatment schedules like plasmaphresis, IVIG, etc needs further RCT studies